Mammography information is used for example for breast cancer screening. During mammography a breast under examination is mechanically compressed and subsequently a radiographic image of the flattened breast tissue is acquired. The mechanical compression of the breast prevents motion artefacts in the images. Moreover, the compression helps to obtain a homogeneous breast tissue thickness and to spread breast structures.
The compression is usually controlled by a compression force which may for example be equal for each patient. According to the European Guidelines for Quality Assurance in Breast Cancer Screening and Diagnosis (N. Perry et al. 2006, 4th edition, Office for the Official Publications of the European Communities, Luxembourg) a maximal compression force between 130 and 200 N is suggested.
U.S. Pat. No. 5,335,257 suggests a compression control in which the compression depends on a compression height of the breast under examination. The compression force is increased as long as the compression height decreases, i.e. as long as the breast is still pliable. However, the compression often causes discomfort.